FGF5 missense mutation is associated with dromedary hair length variation.

Several FGF5 mutations are associated with hair length variation in many domestic animals, including New World camelids. The dromedary was investigated in the present study with breeds exhibiting marked variations in hair length. This study aimed to: (1) identify the molecular variation(s) in the three exons of FGF5 of a diverse group of breeds (Mejaheem, Shaele, Sofor, Waddah and Omani; n = 28); (2) examine the association of the identified variants with hair length; (3) validate the association via genotyping the polymorphism in a large population of diverse camels (n = 113); and (4) test the segregation of the identified variant with hair length in a pedigree. A non-synonymous mutation (c.779 C > T) was identified that changes the amino acid from proline to leucine and was found to be associated with different hair length in dromedaries. The variants at c.779 displayed a co-dominance mode of inheritance and three hair length phenotypes: short (C/C), intermediate (C/T) and long (T/T). Across the examined dromedary breeds, both alleles were present, which is probably due to the breeders' preference for an intermediate hair length. When compared with other camelids, the identified variant was found exclusively in dromedaries with the ancestral allele at c.779 being 'C'. This study constitutes the first thorough exploration of the FGF5 gene in dromedaries.

Genomic prediction for growth using a low-density SNP panel in dromedary camels.

For thousands of years, camels have produced meat, milk, and fiber in harsh desert conditions. For a sustainable development to provide protein resources from desert areas, it is necessary to pay attention to genetic improvement in camel breeding. By using genotyping-by-sequencing (GBS) method we produced over 14,500 genome wide markers to conduct a genome- wide association study (GWAS) for investigating the birth weight, daily gain, and body weight of 96 dromedaries in the Iranian central desert. A total of 99 SNPs were associated with birth weight, daily gain, and body weight (p-value < 0.002). Genomic breeding values (GEBVs) were estimated with the BGLR package using (i) all 14,522 SNPs and (ii) the 99 SNPs by GWAS. Twenty-eight SNPs were associated with birth weight, daily gain, and body weight (p-value < 0.001). Annotation of the genomic region (s) within ± 100 kb of the associated SNPs facilitated prediction of 36 candidate genes. The accuracy of GEBVs was more than 0.65 based on all 14,522 SNPs, but the regression coefficients for birth weight, daily gain, and body weight were 0.39, 0.20, and 0.23, respectively. Because of low sample size, the GEBVs were predicted using the associated SNPs from GWAS. The accuracy of GEBVs based on the 99 associated SNPs was 0.62, 0.82, and 0.57 for birth weight, daily gain, and body weight. This report is the first GWAS using GBS on dromedary camels and identifies markers associated with growth traits that could help to plan breeding program to genetic improvement. Further researches using larger sample size and collaboration of the camel farmers and more profound understanding will permit verification of the associated SNPs identified in this project. The preliminary results of study show that genomic selection could be the appropriate way to genetic improvement of body weight in dromedary camels, which is challenging due to a long generation interval, seasonal reproduction, and lack of records and pedigrees.

Comparative growth response related to hair mineral analysis in dromedary camel calves.

Background: The dromedary camel plays a significant role in supporting the livelihood of pastoral and agropastoral systems, as well as a source of income for the national economy in arid regions. Aim: The current study was executed to check the comparative growth response in relation to hair mineral status in Marecha camel calves reared under an intensive management system and an extensive management system in Thal desert Punjab, Pakistan. Methods: Twelve male and female Camelus dromedarius calves of almost the same weight and age were divided into two groups of 6 each (3 male and 3 female). The calves of the first group were maintained at the Camel Breeding and Research Station, Rakh Mahni, in a semi-open housing system, while the second group was maintained in available housing under field conditions. Calves in the first group were fed concentrate at the rate of 1 kg/head/day along with gram straw (Cicer arientinum) ad libitum, while calves in the second group were allowed to graze/browse for 10 hours daily along with household refusals, including kitchen wastes. Water was provided twice a day. Impressum's digital weighing scale was used for fortnightly weighing. Data collected on different parameters were subjected to statistical analysis with 2 × 2 factorial arrangements of treatments under a completely randomized design. Results: After the 120-day trial period, the mean body weight and average daily gain of male and female calves were significantly increased (p < 0.05) in IMS as 80.8 ± 2.7, 77.8 ± 2.7 kg and 0.67 ± 0.02, 0.65 ± 0.02 kg/days than EMS as 64.5 ± 2.6, 52.9 ± 2.6 kg and 0.54 ± 0.02, 0.44 ± 0.02 kg/days. Intake of crop residues (p < 0.05) was found to be 6.9 ± 0.45 and 6.4 ± 0.45 kg/days for male and female calves in IMS, respectively, and 3.5 ± 0.23 for male and female calves in EMS, respectively. The conversion index g/kg average daily intake was 97.1, 101.5 and 154.3, 125.7 for male and female calves in IMS and EMS, respectively. Regarding hair mineral status, Ca, Mg, Cu, Zn, Fe, and Mn concentrations were found to be significantly different (p < 0.05) among calf groups in IMS and EMS. Conclusion: This study indicates that wool analysis and management of weight gain in camel calves should be further explored to support increased meat supply in arid regions.

Analysis of variation in growth and spline-based growth models for Marecha and Lassi dromedary camels.

Camel is an important domestic animal that is well adapted to extremely harsh environments. Due to its multi-purpose role, the camel is gaining importance, particularly as a meat producer. Body weights at different ages and growth curves have been extensively studied in several livestock species. However, the information on the camel is very limited. We investigate patterns of variation in birth weight and weaning weight of two prominent breeds of camels in Pakistan, namely Marecha and Lassi. A further objective is not only to develop growth models which will account for systematic differences due to breed and sex but also to allow for individual variation in growth, by the application of appropriate statistical models. Birth weight, weaning, and monthly weights for a period of up to 48 months were recorded for each camel. Growth records of 137 camels consisting of 108 Marecha and 29 Lassi were obtained. Differences were detected between the two breeds, Marecha and Lassi, as well as differences between sexes, but only after 2 years of age. Beyond that, female Marecha camels had slower growth than males, whereas Lassi (mostly females) had faster growth than female Marechas. In addition, there is a sizable variation between individuals within the same breed-sex combination. The results of the present study will be of use to explore the potential of the camel as a meat producer in Pakistan.

Cefotaxime pharmacokinetics in Arabian camel (Camelus dromedarius) calves after single intravenous injection.

Cefotaxime is a third-generation broad-spectrum cephalosporin acting on a wide range of Gram-positive and Gram-negative bacteria. In this work, the pharmacokinetics of cefotaxime were determined in dromedary camel calves by single intravenous injection of 10 mg/kg b.w. Cefotaxime levels were estimated by ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Cefotaxime pharmacokinetics in camel calves obeyed three-compartment kinetics model. There was a central compartment and two peripheral, one shallow and one deep compartment. The shallow compartment equilibrates very rapidly with distribution half-life (t1/2α) of 0.6 min, while the deep compartment has large distribution half-life (t1/2ß) of 42 min indicating slower uptake of cefotaxime. The elimination rate constant (γ = 0.04 h-1) and elimination half-life (t1/2 γ) = 15.46 h indicating slow elimination. In comparison with other animals, cefotaxime pharmacokinetics in camel calves showed potential wide distribution in multi-compartment, lower elimination constant, lower clearance and higher volume of distribution at steady state. This indicates substantial differences in cefotaxime pharmacokinetics in camel calves with a very characteristic ultra-rapid distribution into three-compartment and slow elimination.

Effects of a long-acting trace mineral rumen bolus supplement on growth performance, metabolic profiles, and trace mineral status of growing camels.

A study was conducted to evaluate the effects of a long-acting trace mineral rumen bolus (TMB) supplement on the productive performance, metabolic profiles, and trace mineral status of growing camels under natural grazing conditions. Fifteen 6-month-old growing male camels (average bodyweight 139.51 ± 26.49 kg) were used in a 150-day trial. Animals were individually housed in a shaded pen and randomly assigned to receive zero (control group, CON), one (TMB1), or two (TMB2) long-acting TMBs. Feed intake was measured weekly, and camels were weighed monthly. Blood samples were collected from all camels on days 1, 30, 60, 90, 120, and 150 to obtain metabolic profiles. Zinc, selenium, copper, cobalt, and manganese concentrations were determined in the diet, serum, and liver. In comparison with controls, giving camels one TMB increased the average daily gain (14.38%; P < 0.04) and feed efficiency (13.68%; P < 0.01). Additionally, the serum and liver concentrations of zinc, copper, selenium, cobalt, and manganese were greater (P < 0.01) in camels in the TMB2 group. These data indicate that TMB supplementation has positive effects on the growth performance and trace mineral profiles of camels. Different levels, sources, and synergistic combinations of trace minerals can be used in further studies to elucidate their abilities to increase productive variables as well as their availability and cost to the camel industry.

Transabdominal ultrasonography for pregnancy diagnosis and estimation of gestational age in dromedary camels.

The objective of this study was to evaluate the use of transabdominal ultrasonography as a method for pregnancy diagnosis and establish some foetal biometrics guidelines of pregnancy staging. Transabdominal ultrasonography was performed weekly on six pregnant camels from the 4th to the 19th week and at 2-week intervals from the 20th to the 52nd week of gestation. Six areas were selected for examination: caudal abdominal (CAA), inside the thigh, above the base of the udder; middle abdominal (MIA), from the base of the udder to the umbilicus; and cranial abdominal (CRA), from the umbilicus to the xiphoid cartilage. Several foetal parameters including orbital diameter (ORD), biparietal diameter (BPD), abdominal diameter (ABD), chest depth (CHD) and ruminal diameter (RUD) were measured using standardized scan plans. The relationships between the gestational age and the foetal parameters were evaluated. From the 6th to the 12th week, the conceptus was always observed through the left CAA approach. Between the 13th and 27th week, the foetus was entirely visualized by the MIA examination. From the 28th to the 52nd week, the conceptus was mainly detected through the left CRA approach. The foetal parameters were measured frequently during mid- and late gestation. All regression and correlation coefficients were highly significant (p < 0.0001). In conclusion, transabdominal ultrasonography was shown to be a reliable technique for pregnancy diagnosis and estimation of gestational age in dromedary camels.

Evaluation of the effects of chromium supplementation on growth and nitrogen balance of camel calves under summer conditions.

One of the most important problems in the production of camels in arid and semi-arid zones is the reduced feed intake and consequent low growth rate during summer. Under these stressful environmental conditions, chromium (Cr) supplementation to the diet of growing camel calves may be beneficial. Therefore, the objective of this study was to evaluate the effects of feeding a diet supplemented with different levels of Cr on growth performance of camel calves reared in a hot arid environment. A total of 15 male camel calves (4-5-month-old, 123 ± 7 kg body weight) were used in this study. The animals were divided into three equal groups (A, B, C), 5 animals each, and housed individually under shelter. Camel calves were fed ad libitum on either total mixed ration (TMR) without Cr supplementation (group A), TMR supplemented with 0.5 mg Cr/kg DM (group B), or TMR supplemented with 1.0 mg Cr/kg DM (group C). Supplementation of 0.5 mg Cr/kg DM to the diet of camel calves did not alter feed intake, however, increased not significantly (P = 0.086) average daily gain (ADG) and N retention. Plasma cortisol level was reduced by 10%, and feed utilization efficiency was improved by 12% in 0.5 mg Cr/kg DM-supplemented group compared to the control. Thus, 0.5 mg Cr/kg DM dietary supplementation to camel calves reared under hot summer condition increased weight gain by 17% and reduced feeding cost of producing a unit of weight by 11%.

Intraocular pressure in clinically normal dromedary camels (Camelus dromedarius).

OBJECTIVE: To determine the intraocular pressure (IOP) in healthy dromedary camels (Camelus dromedarius). ANIMALS: 24 clinically normal dromedary camels. PROCEDURES: For each camel, the IOP of both eyes was measured with applanation tonometry. Three measurements with < 5% variance were obtained for each eye on the same day of the week for 3 consecutive weeks. Mean IOP was calculated for each eye on each day for comparison purposes. RESULTS: Mean ± SD IOPs for the right (31.1 ± 2.1 mm Hg) and left (30.8 ± 1.9 mm Hg) eyes of immature camels were significantly higher than those for the right (27.1 ± 1.2 mm Hg) and left (28.2 ± 1.2 mm Hg) eyes of mature camels. Intra-assay and interassay coefficients of variation (CVs) for IOP measurements of the right and left eyes did not differ significantly between immature and mature camels. Interassay CVs of IOP measurements for the right and left eyes ranged from 1.5% to 12.1% and 1.2% to 10.3%, respectively, for immature camels and from 1.2% to 17.2% and 1.7% to 18.8%, respectively, for mature camels. Intra-assay CVs of IOP measurements for the right and left eyes ranged from 1.5% to 10.6% and 1.9% to 9.6%, respectively, for immature camels and from 2.8% to 16.9% and 2.7% to 12.4%, respectively, for mature camels. Age was negatively correlated (r = -0.403) with IOP. CONCLUSIONS AND CLINICAL RELEVANCE: Results provided a reference and might aid in the diagnosis of glaucoma and uveitis during complete ophthalmic examinations of dromedary camels.

Impact of feeding on growth performance, blood biochemical and mineral profiles of pre-pubescent camels under pastoral management in arid western Rajasthan.

The experiment was undertaken on 20 pre-pubescent dromedary camels of 300 ± 7.0 kg average bodyweight (BW) and 1.5-2 years of age to determine change in body weight, blood biochemical and mineral profiles and morphometric parameters on rangeland grazing (GR) and supplementary stall feeding (GS) at arid northwestern part of Rajasthan over a period of 80 days. GR camels were maintained only on grazing, while GS camels were fed semi-intensively ad-lib groundnut haulms along with formulated concentrate and mineral mixture to meet maintenance requirement. Intake of young camels was determined using chromium(III) oxide as internal marker. The biomass yield of rangeland estimated was 0.54 t DM/ha. Dry matter intake (kg/day) by GR camels on rangeland grazing was lower than that by GS camels fed on supplementary feeding. The nutrient digestibility of dry matter and organic matter (P < 0.05) and crude protein was higher in GS camels than that in GR camels. Likewise, intake of digestible crude protein (P < 0.05) and metabolizable energy were higher in stall-fed young camels. Pre-pubescent camels fed on grazing had significantly (P < 0.01) low glucose and higher urea concentration compared to stall-fed camels. Final body weight of camels differed significantly (P < 0.05) between groups. The camels fed on supplementary stall feeding had significantly (P < 0.01) higher total gain (kg) and average daily gain (ADG) compared to camels on grazing. Among morphometric parameters, body length and body height showed more significant increase in GS compared to GR camels. Intake of digestible crude protein (DCP) by GR group was 43% low compared to the requirement for growing camel of 300 kg body weight. Despite this, GR camels were able to maintain body weight due to better recycling of urea which was significantly higher in comparison to GS camels. The findings of significantly (P < 0.01) low serum glucose and higher urea concentration and lower body weight gain of GR camels suggest the need of locally available protein and energy supplement in addition to grazing for better growth performance.

Prenatal development of the eye tunics in the dromedary camel (Camelus dromedarius).

Studies of ocular development in the dromedary camel (Camelus dromedarius) have not been reported previously. The aim of the present investigation was therefore to document the major landmarks and the time course in the prenatal development of the eye tunics in dromedary camel and its accommodation with the surrounding hard environment of the desert. Serial histological sections of dromedary camel embryos and foetuses were used. Age estimation was made on the basis of gestational size, crown vertebral-rump length (CVRL), which ranged 1.2-110 cm. The eye of the dromedary camel developed in a similar manner to that of the human and domestic animals eyes; the principal differences were in the time of occurrence of certain developmental events, pigmented peripheral cornea near the limbus, a remarkably thickened Descemet's membrane and pigmentation in the corneo-scleral junction, which represent an adaptive modification in relation to a severe environment.

Osteometry of the skull of one-humped camels. Part I: immature animals.

The aim of this study was to investigate osteometric indices of immature camels (2-3 years old) in Nigeria. The cranial length, viscerocranial length, maximum zygomatic width, neurocranial volume, skull and facial index for females and males were 22.1 cm and 22.3 cm; 16.3 cm and 16.7 cm; 15.8 cm and 16.1 cm; 479 ml and 496 ml; 40.9 and 41.3, and 96.4 and 96.2 respectively. The mean orbital horizontal and vertical diameters of young camels were similar to each other giving a near complete circular shape. The foramen magnum index was over 100 because of a relatively higher height than width. The data were compared with those of other types of immature camels in the literature and will be useful for anatomical, developmental, anthropological and clinical studies of camels.

The histological characteristics of the aggregated lymphoid nodules area in abomasum of Bactrian camels (Camelus bactrianus) of different ages.

The aggregated lymphoid nodules area (ALNA) in abomasum of Bactrian camels is a special immune structure discovered only in Bactrian camels in recent years (2003). The anatomy research found that there was a close relationship between degree of development, anatomical characteristics and age. To further establish the relationship between histological characteristics of this special structure and animal age, 24 Alashan Bactrian camels of the following four age groups were studied: young (1-2 years), pubertal (3-5 years), middle-aged (6-16 years) and old (17-20 years). Mucosal-associated lymphoid tissue (MALT) of ALNA in abomasum was particularly observed and analyzed by histology, histochemistry and statistical methods. The results showed that the average number of lymphoid nodules in reticular mucosal folds region of ALNA in abomasum from young group to old group was in order of 26.8, 32.7, 17.6 and 7.8, and in longitudinal mucosal folds region was 20.1, 26.0, 10.3 and 5.1. The number of lymphoid nodules in the four experimental groups first increased and then decreased with increasing age (P<0.01). In young and pubertal camels lymphoid nodules were distributed evenly on both sides of the axis of mucosal folds and mostly displayed round, oval or wedge shape. The number of lymphoid nodules, follicle-associated epithelium (FAE), reticular fibers and plasmocytes in mucosal folds gradually increased from 1 to 2 years and peaked at puberty. There were up to 37 visible lymphoid nodules in a mucosal fold. However, ALNA of middle-aged and old camels gradually degenerated as aging. Lymphoid nodules were unevenly distributed on both sides of the axis of mucosal folds, which mostly displayed oval or irregular shape. Lymphoid tissue in old camels mostly existed as diffuse form. Although germinal centers of the lymphoid nodules were still obvious, the number of reticular fiber and plasmocyte and lymphoid nodules gradually decreased. The results indicated that in accord with the anatomical results, there was a close relationship between histology characteristics of lymphoid tissue of ALNA in abomasum and animal age. In summary, the lymphoid tissue of ALNA in abomasums gradually increased from young to pubertal groups with increasing age, peaked in 3-5 year-old camels, and subsequently declined with age and when 17-20 years old this immunity structure had severely atrophied.

Effect of feeding different proportions of groundnut haulms (Arachis hypogaea) and cluster bean straw (Cyamopsis tetragonoloba) on nutrient utilisation and serum biochemical parameters in dromedary camels.

The effect of feeding different proportions of groundnut haulms (Arachis hypogaea) and cluster bean straw (Cyamopsis tetragonoloba) on nutrient digestibility, nutritive value, nutrient intake and serum biochemical parameters was studied using nine male dromedary camels of Bikaneri breeds (637.5 kg average body weight; 8-9 years of age). Groundnut haulms (GNH) and cluster bean straw (CBS) were fed in one of three ratios, 75:25, 50:50 and 25:75 in treatments T(1), T(2) and T(3), respectively. In all treatments, concentrate mixture was fed as per requirement of the camels. The groundnut haulms were more nutritive as compared to the cluster bean straw. The nutrient digestibility of dry matter, organic matter, crude protein (CP), crude fibre and acid detergent fibre was better in T(1) than T(2) and T(3). Likewise, the CP, digestible crude protein and total digestible nutrient contents were significantly higher in T(1) followed by T(2) and T(3). There was non-significant affect on average daily gain of camels. However, dry matter intake, digestible crude protein intake and total digestible nutrients were better in T(1) as compared to T(2) and T(3). The total water intake per kilogram of dry matter intake (litres) was 2.98, 2.89 and 2.68, respectively, in T(1), T(2) and T(3). The camels in all the treatments were in positive nitrogen, calcium and phosphorus balance. The treatments had a significant effect on serum biochemical parameters like glucose, cholesterol, aspartate transaminase and creatinine. The results may conclude that feeding of higher proportion of groundnut haulms as compared to cluster bean straw has pronounced improvement in nutritional utilisation by the camels.

Reference values for the genitalia of male dromedary before and after puberty using caliper and ultrasonography in subtropics.

The aim of the present study was to characterize the dynamic changes of the testes and the pelvic genitalia in vivo in male dromedary. Eighty-one clinically healthy male dromedaries aged 1.5 to 12 years were assigned for the present study. Testicular length, breadth, and depth as well as epididymal head and tail were measured using caliper and ultrasonography. The pelvic genitalia, including bulbourethral gland, prostate, and pelvic urethra were examined using ultrasonography. The results revealed that the three dimensions of the testes and epididymal tail and head showed significant increase with age (P < 0.01). Concerning the epididymal measurements, differences between the pre- and peri-pubertal groups were not significant. Left testes tended to be larger than the right (not statistically significant) although only the breadth of the left testes in the prepubertal group was significantly larger (P < 0.05). The volume of both testes correlated positively with the age (r(2) = 0.91 for left and 1.00 for the right, P < 0.01). There were no significant correlations between the values measured using caliper and those by ultrasonography between groups, but the correlation was highly significant (P < 0.01) for the total number of the examined animals. There were significant and steady increases of the size of bulbourethral gland in all examined groups (P < 0.01). Pars disseminata of the prostate gland and pelvic urethra were significantly higher in sexually mature compared with prepubertal groups (P < 0.01). It was concluded that ultrasonography is a useful tool in studying the developmental changes of the testes and accessory glands of the male dromedary. The obtained data could provide a reference values for predicting camel puberty and future fertility.

A comparative assessment of the size of the frontal air sinus in the giraffe (Giraffa camelopardalis).

The current study examines the frontal air sinus of the giraffe (Giraffa camelopardalis) cranium with the aim of evaluating previously offered hypotheses as to why they have such an atypically voluminous frontal sinus relative to other artiodactyls. To date, no quantification of the frontal sinus in the adult or developing giraffe has been undertaken or compared to other artiodactyl species. Crania from eight species of adult artiodactyls, and giraffes varying in age from newborn to adult, were studied using CT scans to provide a volumetric assessment of the frontal sinus. Sinus volume was strongly correlated to cranial mass in the male giraffe ontogenetic series. The adult giraffe of both sexes were found to possess a far larger than predicted sinus volume relative to the relationship between frontal sinus volume and cranial mass observed in the other adult artiodactyls. Our results suggest that the volume of the frontal sinus in the giraffe is likely to be unique among artiodactyls, and the potential function and evolution we consider in light of several previously articulated hypotheses.

Genetic and nongenetic effects for milk yield and growth traits in Saudi camels.

The study was based on a set of 256 records for milk yield at 305 days, 1,899 records of test day yield, and 466 growth records collected at Al Jouf center from 1987 to 2009. Except season of calving, milk yield at 305 days was affected by parity and calving year, whereas test day yield was influenced by parity, calving year, stage of lactation, and test milk day. Only birth year had a significant effect on all growth traits, whereas dam's parity influenced weights at birth and 3 months, and birth season affected birth weight, weight at 6 months and average daily gain (ADG) 3-6 months. Variance components estimated using an animal model showed that heritability and repeatability estimates for milk yield at 305 days were 0.24 and 0.28, respectively. The corresponding estimates for test day yield were 0.22 and 0.66, respectively. Direct heritabilities were 0.37, 0.50, 0.60, and 0.85 for body weights at birth, 3, 6, and 12 months of age, respectively, and 0.25, 0.37, 0.49, and 0.29 for ADG 0-3, 3-6, 6-12, and 0-12 months, respectively. The annual genetic progress was 0.05 kg for milk yield at 305 days and 0.0003 kg for test day yield. Annual genetic gains during 23 years were 0.050, -0.185, 0.079, and 0.331 kg for body weights, respectively, and -9, -5, -4, and -13 g, for ADG, respectively. It was concluded that it is necessary to set up a field milk and growth recording system in order to collect a large number of records to check these estimates.

Seasonal variation in blood constituents of one-humped camel (Camelus dromedarius).

This study was carried out in southern Darfur, Sudan during dry-and green (wet) season and was designed to investigate the effects of season (dry-versus green season) on the blood constituents of the one-humped camel (Camelus dromedarius). Two hundred and ten blood samples collected from apparently healthy one-humped camels (Camelus dromedarius) of different age and sex groups were used in this study, out of which 110 blood samples were collected during the dry season, while 100 blood samples were collected during the green season. The data analysis revealed that the season had significant effects on some of the haematological indices and the blood metabolites and minerals concentrations. The red blood cells count, lymphocytes and basophils percentages increased significantly during the dry season, while the osmotic resistance, MCV, MCH and neutrophils percentage increased significantly during the green season. The serum levels of total protein, globulins and triglycerides increased significantly during the dry season, while the concentrations of plasma glucose and serum urea, creatinine, phosphorus (P) and calcium (Ca) increased significantly during the green season. The results obtained in the present study indicate that the nutritional status could induce significant changes in the physiological responses of the dromedary camel. The available forage during the green season improved the body condition, the blood metabolic and mineral profile in camels. The results indicate that despite camel's selectivity and unique adaptation to arid conditions; glucose, urea, P and Ca levels were lower during the dry season. Therefore, it could be beneficial to provide concentrate feed to camels kept under dry tropical conditions.

The zinc and copper content of the plasma of Sudanese camels (Camelus dromedarius).

A study was undertaken to investigate the variations in the content of zinc and copper in the plasma of Sudanese camels (Camelus dromedarius). A total of 993 Arabi camels, aged 0.5-8 years, were used to assess the effect of season, age, sex and physiological status on the plasma concentrations of copper and zinc. There was an increase in the concentration of Cu and a decrease in the concentration of Zn in the plasma with age. The concentrations of both Cu and Zn in the plasma were higher in the rainy season than in the dry season. The plasma copper concentrations in pregnant, low-lactating and high-lactating camels were 81.3 +/- 4.7, 59.7 +/- 6.1 and 61.3 +/- 5.5 microg/100 ml, respectively. The corresponding values for zinc were 51.0 +/- 8.9, 53.4 +/- 6.4 and 67.1 +/- 5.5 microg/100 ml, respectively. However, there was no effect of sex on the content of these minerals in the plasma.

Intratesticular morphometric, cellular and endocrine changes around the pubertal period in dromedary camels.

We obtained the paired testes from 66 clinically healthy camels during two consecutive breeding seasons. Testicular tissues were examined for peripubertal changes in histological structure as well as spermatogenic and steroidogenic activities. Cellular sizes (length microm x width microm) increased linearly (P< 0.05) throughout the first three years of the animal's life for Leydig cells and between two and a half and five years of age for Sertoli cells. A clear increase in the percentage of tubules demonstrating primary and secondary spermatocytes occurred between less than one and five years and a cohort of elongated spermatids was produced in 3.5 +/- 0.2% tubules in males of two and a half years old; the appearance of spermatozoa in 3.1 +/- 0.3% tubules was evident six months later. The basal values for intratesticular and plasma concentrations of oestradiol-17 beta and testosterone respectively, were measured in all animals up to one and a half years for oestradiol-17 beta and three years for testosterone. Thereafter, both steroids increased markedly (P< 0.01) peaking to 269.5 +/-27.1 pg/g and 83.4 +/- 8.3 pg/mL at three years for oestradiol-17 beta and to 164.7 +/- 16.8 ng/g and 6.8 +/- 0.7 ng/mL at five years for testosterone. The results suggested that a steroid hormonal shift around four and a half to five years of age could demarcate the beginning of pubertal period which culminates with the production of the first ejaculum containing higher concentrations of spermatozoa by dromedary camels of six years old.